We develop a stock return-predictive measure based on an efficient aggregation of the portfolio holdings of all actively managed U.S. domestic equity mutual funds, and use this model to study the source of fund managers' stock-selection abilities. This generalized-inverse alpha (GIA) approach...

This paper shows that publicly disclosed mutual fund portfolio holdings have investment value. Our approach is based on the intuition that an overweighting by successful managers, or an underweighting by unsuccessful managers signals that a stock is currently underpriced. Investment strategies...